WO2004031009A1

WO2004031009A1 - Emergency braking apparatus for vehicle

Info

Publication number: WO2004031009A1
Application number: PCT/JP2003/012441
Authority: WO
Inventors: Moriharu Sakai; Takashi Watanabe; Shoichi Masaki
Original assignee: Advics Co., Ltd.
Priority date: 2002-10-04
Filing date: 2003-09-29
Publication date: 2004-04-15
Also published as: DE10393012T5; US20050162012A1; CA2492365A1; JPWO2004031009A1; CA2492365C; US7213687B2; CN100360351C; CN1671584A

Abstract

An emergency braking apparatus for a vehicle capable of accurately operating a second braking means in an emergency, comprising the second braking means (1) for braking the vehicle (A) by increasing the frictional resistance thereof with a road surface, a millimeter wave radar (2) for detecting an obstacle in a traveling direction, a pedal speed sensor (5) for detecting the depressing speed of a brake pedal (4) operating a first braking means, and a controller (6) for operating the second braking means (1), wherein when an emergency braking by the first braking means is detected by the pedal speed sensor (5), the controller (6) determines whether or not the vehicle (A) is collided with the obstacle detected by the radar (2) and when the controller determines to be collided, operates the second braking means (1), whereby the second braking means (1) can be accurately operated in an emergency.

Description

Specification

Emergency braking device for vehicles

The present invention relates to an emergency braking device for a vehicle for urgently avoiding a collision of the vehicle. Background art

When the vehicle travels on a road surface with a low coefficient of friction, such as a frozen road, a wet paved road, or a dry paved road with sand, the tire grip on the road surface decreases and the wheels become slippery. For this reason, in the braking device (first braking means) for braking the rotation of the wheel conventionally mounted on the vehicle, the braking distance becomes significantly long even if the sudden braking is operated, and the vehicle is slow regardless of low speed. It may collide with an obstacle.

On a road surface with such a low coefficient of friction, the degree of slippage tends to be uneven among the wheels, so the running of the vehicle becomes unstable and the vehicle may collide with an obstacle in the diagonal direction. As a means to make the vehicle run stably, the degree of slippage is detected for each wheel, and the braking force of each wheel is controlled by an ABS (Antilock Brake System), a yaw rate sensor or a lateral acceleration sensor. Devices such as VSC (Vehicle Stabil- ity Control), which detect the steering tendency and control the engine power and wheel braking force, have been put to practical use, but these devices work effectively. The assumption is that tire grip strength remains to some extent. In order to prevent the collision of the vehicle on the road surface with a low coefficient of friction as described above, a second braking means for braking the vehicle in a short distance by raising the frictional resistance with the road surface separately from the conventional brake device. It has been proposed to be loaded. As this second braking means, an anti-slip material such as sand or ice is dispersed between the tire and the road surface (see, for example, Patent Documents 1 to 3), and liquid adhesive is applied to the tire surface. Applying an agent to adhere the anti-slip material to the tire (see, for example, Patent Document 4), blowing cold air onto the tire to prevent thawing of a freezing path (see, for example, Patent Document 5), A brake plate or a toothed brake wheel is pressed against the road surface (see, for example, Patent Documents 6 to 8). A gas bag is expanded outward of the vehicle to increase the pressing force of the vehicle against the road surface. (See, for example, Patent Document 9).

(Patent Document 1; Japanese Patent Application Laid-Open No. 4-3 0 2 0 4, Patent Document 2; Japanese Patent Application Laid-Open No. 7-3 0 0 9 0 1, Patent Document 3; Japanese Patent Application Laid-Open No. 8-2 5 0 5 0, Patent Document 4; JP-A 6 3-2 7 0 Patent Publication 6; Patent Literature 5; JP-A-50-0. 0703; Patent Literature 6; JP-A-491-2225: Patent Document 7; JP-A-8-42022; JP-A-6-286 586; JP-A-8-42022; ) Disclosure of the invention

Since the second braking means mentioned above takes time and effort to recover once it is activated or there are many things that are difficult to recover, it is desirable to avoid unnecessary actuation and activate only in the emergency that really needs actuation. Be

Therefore, an object of the present invention is to provide an emergency braking device for a vehicle which can properly operate the second braking means in an emergency situation.

In order to solve the above problems, an emergency braking device for a vehicle according to the present invention comprises: a first braking means for braking the rotation of a wheel; and a second braking for raising the frictional resistance with the road surface to brake the vehicle. Means, obstacle detection means for detecting an obstacle in the traveling direction, and collision judgment means for judging whether or not the vehicle collides with the obstacle detected by the obstacle detection means; When it is determined that the vehicle collides, the second braking means is operated. The obstacle detection means may be a reflected wave from an obstacle of an elastic wave such as laser, visible light, infrared light, millimeter wave, radio wave, electromagnetic wave such as radio wave, magnetism, etc., or a sensor itself emitting an obstacle. , Radar, TV camera, etc., a method of using the emitted waves of these electromagnetic waves or elastic waves as a beacon, a method of viewing an incident wave in stereo or image processing, further, PS (Global Positioning System) The “VI (Vehicle information Communication System) can be used.

As the collision judging means, a method of calculating whether the vehicle collides with the obstacle is adopted from the distance between the obstacle and the vehicle detected by the obstacle detecting means, and the speed and acceleration / deceleration of the vehicle. be able to.

A sudden braking detection means is provided for detecting a sudden braking operation by the first braking means or an operation request for a sudden braking by the driver, and the sudden braking detection means detects the sudden braking operation or the operating request. When the collision determination means determines whether the vehicle collides or not, the second braking means can be more accurately operated in an emergency situation.

There is provided a sudden braking force increasing means for automatically increasing the sudden braking performed by the driver by the first braking means, and when the collision judging means judges that the vehicle collides, the rapid braking force increasing means is operated. If it is determined that a collision still occurs, operate the second braking means In this way, it is possible to make use of the rapid braking boosting means and reduce the situation where the second braking means needs to be actuated.

The second braking means is composed of a plurality of different types, and a road surface state detecting means for detecting the state of the road surface is provided, and according to the road surface state detected by the road surface state detecting means, By selecting the two braking means from among a plurality of different types, the more effective type of second braking means can be actuated depending on the road surface condition.

That is, for example, a second braking means of the type that spreads sand between the tire and the road surface is effective for frozen roads, but rather promotes the slip of the wheels on dry paved roads where sand intervenes. Ru. Therefore, by mounting and using a plurality of different types of second braking means, it is possible to effectively operate the second braking means in response to various road surface conditions.

As the road surface condition detecting means, the slips of the respective wheels are similar to those described in Japanese Patent Application Laid-Open Nos. 7-1 1 2 6 5 9 and 2 0 1 2 0 7 0 9 We adopt a method of indirectly estimating the road surface condition from the relationship between the sum of values and the vehicle acceleration, and the frequency response of the transfer characteristic from the road surface disturbance to the wheel speed, and a method of observing the road surface condition directly with a TV camera etc. be able to.

When the second braking means is actuated, there is no sudden braking by the first braking means, and it is determined that the collision judging means avoids a collision of the vehicle with an obstacle. Or When the vehicle is determined to be stopped, stopping the operation of the second braking means allows the sand, ice particles, etc. to be prevented from slipping when the second braking means is activated. The extra use of cold air etc. can be saved.

By emitting a warning sound when operating the second braking means, it is possible to make the driver or the passenger take a stance against an impact or the like when the second braking means is operated. The emitted warning sound may be stopped when it is judged that the collision of the vehicle is avoided, or when the operation of the second braking means is stopped.

The emergency braking device for a vehicle according to the present invention comprises: a first braking means for braking the rotation of wheels; a second braking means for braking the vehicle by increasing the frictional resistance with the road surface; and an obstacle in the traveling direction An obstacle detection unit, and a collision determination unit that determines whether the vehicle collides with the obstacle detected by the obstacle detection unit, and when the collision determination unit determines that the vehicle collides, Since the second braking means is operated, the second braking means can be properly operated in an emergency situation, and unnecessary operation of the second braking means, which takes time for recovery, can be avoided. There is provided a sudden braking detection means for detecting a sudden braking operation by the first braking means or an operation request for a sudden braking by the driver, and when the sudden braking detection means detects a sudden braking operation or a demand for operation. The second braking means can be more accurately operated in an emergency situation by judging whether the vehicle collides or not by the collision judging means.

There is provided a sudden braking force increasing means for automatically increasing the sudden braking performed by the driver by the first braking means, and when the collision judging means judges that the vehicle collides, the rapid braking force increasing means is operated, If it is determined that the vehicle still collides, by operating the second braking means, it is possible to utilize the rapid braking boosting means to reduce the situation where the second braking means needs to be operated.

The second braking means is composed of a plurality of different types, and a road surface condition detecting means is provided for detecting the condition of the road surface, and the second braking is provided according to the road surface condition detected by the road surface condition detecting means. By selecting the means from a plurality of different types, a more effective type of second braking means can be activated depending on the road conditions.

After the second braking means is actuated, there is no sudden braking operation by the first braking means, and it is determined that the collision determination means avoids collision of the vehicle with an obstacle, or When it is determined that the vehicle is at a standstill, the second braking means is stopped to prevent excess sand such as sand or ice particles from blowing on the anti-slip material tire when the second braking means is activated. Use can be saved.

By emitting a warning sound when operating the second braking means, it is possible to make the driver or the passenger take a stance against an impact or the like when the second braking means is operated. Brief description of the drawings

Fig. 1 is a schematic view of a vehicle equipped with the emergency braking system according to the first embodiment, Fig. 2 is a schematic view showing a second braking means of Fig. 1, and Fig. 3 is a vehicle of Fig. 1 FIG. 4 is a schematic block diagram of a vehicle equipped with the vehicle emergency braking device according to the second embodiment, and FIG. 5 is a schematic diagram of the vehicle shown in FIG. FIG. 6 is a flowchart showing an algorithm for operating the emergency braking device, and FIG. 6 is a flowchart showing an algorithm for operating the emergency braking device for a vehicle of the third embodiment. Form

Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 6. Figures 1 to 3 show 1 shows one embodiment. As shown in FIG. 1, this emergency braking system for a vehicle includes second braking means 1 for dispersing friction prevention material against the road surface by dispersing anti-slip material between the tire and the road surface, and A radar 2 using a mill wave to detect obstacles, and a second to brake the rotation of each wheel 3

A pedal speed sensor 5 for detecting the depression speed of the brake pedal 4 for operating the braking means (not shown) of 1 and the radar when the rapid braking is activated by the first braking means

It is determined whether or not the vehicle A collides with the obstacle detected in 2 and, when it is judged that the vehicle A collides, the controller 6 operates the second braking means 1.

A distance L to an obstacle detected by the radar 2 and a stepping speed S of the brake pedal 4 detected by the pedal speed sensor 5 are input to the controller 6.

A threshold S _τ of the stepping speed S, which is used as a determination criterion of the sudden braking of the braking means 1, is set in advance. Although not shown, the controller 6 is also configured to input a vehicle speed V detected by a vehicle speed sensor and a vehicle acceleration α detected by a vehicle acceleration sensor 18.

As shown in FIG. 2, in the second braking means 1, the gas is accumulated in the accumulator 8 by the pump 7, and the accumulated gas is contained in the anti-slip material via the two solenoid valves 9 and 10. The spray material is supplied to the spray material container 1 1, and the solenoid valves 9, 10 are opened according to a command from the controller 6, and the anti-slip material is sprayed from the nozzle 12 disposed in front of the wheel 3. is there. The bypass path 13 of the gas pipe provided between the solenoid valve 1 0 and the nozzle 1 2 injects only the gas from the nozzle 1 2 so that the nozzle 1 2 is not clogged, etc., and the second braking means It is provided for testing to confirm that 1 works properly. Although not shown, the solenoid valves 9, 10, the spray material container 11 and the nozzle 12 are provided for each of the wheels 3. These may be provided only on the front wheel side where the braking effect is large.

FIG. 3 is a flowchart showing an algorithm of the controller 6 for operating the above-described vehicle emergency braking device. First, the controller 6 compares the stepping speed S inputted every moment from the pedal speed sensor 5 with the preset threshold value S _τ (step 1), and when the stepping speed S exceeds the threshold value S _τ , Furthermore, check for the presence of an obstacle on the radar 2 (step 2). If there is an obstacle, the vehicle speed V and the vehicle acceleration (decreased from the vehicle speed sensor and the vehicle acceleration sensor 18) From the speed), the braking distance L _B by the first braking means is calculated by the following equation (step 3).

L _B = V ² / (2 α) (1)

(1) is used to calculate the braking distance L _{として} with the deceleration due to sudden braking as a constant deceleration. It is Advance grasped braking characteristic according to the first brake means, based on the braking characteristics may be corrected braking distance L _B calculated by equation (1). .

Next, the calculated braking distance L _B is compared with the distance L to the obstacle detected by the radar 2 (step 4), and when the braking distance L _B becomes equal to or more than the distance L to the obstacle It is judged that the vehicle collides with an obstacle, and each solenoid valve 9, 10 is opened to operate the second braking means 1 (step 5).

In this embodiment, the operation of the sudden braking by the first braking means is a necessary condition for operating the second braking means 1. However, when the driver's request for operating the sudden braking is a necessary condition, the deceleration is The braking distance L _B may not be predictable as it may not have been started yet. In such a case, for example, when the output of the sensor that detects the operation request of sudden braking exceeds a predetermined threshold, it is judged that the vehicle collides with the obstacle unconditionally, and only the second braking means 1 is operated. It is preferable to The distance L to the obstacle, the vehicle speed V, etc. may be added to this judgment.

4 and 5 show a second embodiment. This emergency braking device for a vehicle is, as shown in FIG. 4, in addition to that of the first embodiment, a second braking means 1 6 for pressing the braking plate 15 to the road surface with a cylinder 14; A second braking means 1 for dispersing the anti-slip material according to the road surface condition observed by the TV camera 17; and a braking plate 1 The second braking means 16 for pressing 5 is selectively operated by the controller 6.

The controller 6 is configured to determine whether the road surface is frozen, wet or dry from the road surface image captured by the TV camera 17. As described above, the road surface condition is estimated indirectly from the relationship between the sum of the slip value of each wheel and the vehicle acceleration, the frequency response of the transfer characteristic from road surface disturbance to the wheel speed, etc. It is also good.

FIG. 5 is a flowchart showing an algorithm of the controller 6 for operating the above-described vehicle emergency braking device. Similar to that of the first embodiment, firstly, the controller 6 compares the depression speed S and闞値S _tau that is constantly inputted (Step 1), when the depression speed S exceeds the threshold value S _tau is Further, check the presence or absence of an obstacle on the radar 2 (step 2), and if there is an obstacle, from the vehicle speed V and the vehicle acceleration (deceleration) a, the braking distance by the first braking means L _B is calculated by equation (1) (step 3), and the calculated braking distance L _B is compared with the distance L to the obstacle (step 4).

When the braking distance L _B becomes equal to or more than the distance L to the obstacle, it is imaged by the TV camera 17 If it is judged that the road surface is dry or other (step 5) and it is judged that the road surface is dry, the second braking means 16 for pressing the brake plate 15 is operated (step 5) 6) At other times, activate the second braking means 1 for spraying anti-slip material (step 7).

The emergency braking device for a vehicle according to the third embodiment is not shown, but based on the output of the pedal speed sensor 5, the controller 6 of the first embodiment shown in FIG. 1 performs the first braking. Incorporating a brake system as a rapid braking intensifying means that automatically boosts the sudden braking performed by the driver by means, the braking distance L _B calculated by the equation (1) is up to the obstacle detected by the radar 2. When the distance L is exceeded, the brake assist system is activated first, and when it is determined that the vehicle A still collides with the obstacle, the second braking means 1 is activated.

FIG. 6 is a flow chart showing the algorithm of the controller 6 for operating the vehicle emergency braking system of the third embodiment. This flow chart omits step 1 in the first embodiment shown in FIG. 3 and operates the brake assist system in the YES path from step 4 to step 5 41, according to the brake assist system braking distance step 4 2 for calculating the L _{B 1,} and step 4 3 is provided to compare the braking distance L _{B 1} and the distance L to the detected obstacle by radar 2, the braking distance L _{B 1} failure The second braking means 1 is operated when the distance L to the object is exceeded.

In the case of providing a rapid braking force increasing means such as the above-mentioned brake assist system, the step of operating the rapid braking force increasing means in the YES path from step 1 to step 2 in the flow chart of the first embodiment shown in FIG. provided, it calculates a braking distance L _B by sudden braking that energizing of the first braking means, which in comparison with the distance L to the obstacle may be a collision determination of the vehicle.

In each of the above-described embodiments, the radar of the milli wave is employed as the obstacle detection means, and the pedal speed sensor of the brake pedal is employed as the sudden braking detection means of the first braking means. The detection means is not limited to any of the embodiments, and various methods as described above can be employed. Also, as the second control means, any means that can increase the frictional resistance with the road surface can be used, and various means as described above can be adopted.

Claims

The scope of the claims

1. first braking means for braking the rotation of wheels, second braking means for controlling the vehicle by increasing frictional resistance with the road surface, obstacle detection means for detecting an obstacle in the traveling direction, And a collision determination unit that determines whether the vehicle collides with the obstacle detected by the obstacle detection unit, and when the collision determination unit determines that the vehicle collides, the second braking unit Emergency braking system for vehicles that is designed to operate.

2. A sudden braking detection means is provided for detecting a sudden braking operation by the first braking means or an operation request for a sudden braking by the driver, and the sudden braking detection means detects the sudden braking operation or the operation request. The emergency braking device for a vehicle according to claim 1, wherein it is determined by the collision determination means whether or not the vehicle collides.

3. A sudden braking force increasing means for automatically increasing the sudden braking performed by the driver by the first braking means is provided, and when the collision judging means judges that the vehicle collides, the rapid braking force increasing means is operated. The emergency braking device for a vehicle according to claim 1, wherein the second braking means is operated when it is determined that a collision still occurs.

4. The second braking means is composed of a plurality of different types, and a road surface state detecting means for detecting the state of the road surface is provided, and according to the road surface state detected by the road surface state detecting means, An emergency braking system for a vehicle according to any one of claims 1 to 3, wherein the second braking means is selected from a plurality of different types.

5. After the second braking means is actuated, it is judged that the sudden braking is not activated by the first braking means, and that the collision judging means judges that the collision of the vehicle with the obstacle is avoided. The emergency braking device for a vehicle according to any one of claims 1 to 4, wherein when the vehicle is determined to be stopped, the operation of the second braking means is stopped.

6. The emergency braking device for a vehicle according to any one of claims 1 to 5, wherein a warning sound is emitted when the second braking means is operated.